Pneumatic printing-frame.



L. F. LEVY.

PNEUMATIC PRINTING FRAME.

APPLICATION HLEU nzc. 20, 1915.

1,246,620. Patented Nov. 13 191-7.

2 SHEETSSHEET I.

L'.F.I .EVY.

PNEUMATIC PRINTING ERA'ME. APPLICATION FILED DECJO. 1915.

1,246,620. Patented Nov. '13, 1917.

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36 3] I gfi- 3|? fi ating in conjunction with the vacuum ducing means to form a tight locking of LIONEL r. LEVY,

Specification of Letters Patent.

or'rnrna nmnm, rENNsYnvANn. rNEUMATIc PRINTING-FRAME.

Patented Nov. 13, 1917.

Application filed December '20, 1915. Serial No. 67,715.

To all whom it ma concern:

Be it known til at I, LIONEL F. LEVY, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have inventeda certain new and useful Improvement in Pneumatic Printing-Frames; of which the following is a specification.

The present invention relates to photographic printing frames for blue prints, copies of pictures, photographic prints on metal plates and wherein means for exhausting air between a mat or blanket and a transparent plate is employed in order to insure a perfect and uniform contact between the negative and the sensitized medium.

The object of the present invention is to provide a of the frame are provided with means, operprothe frame, when the parts are assembled in operative position ready for printin In frames of this character as herein fore constructed, it has been usual and customary to provide a manually operable means for securely clamping the two sections of the frame together and incidentally thereto clamping the edges of the flexible mat or blanket in such almanner as to produce a leak-proof joint whereby a pr oper vacuum condition is maintained between the plate and the blanket.

are not only cumbersome, complicated and require considerabletime in adjusting, butalso are open to the objection that the edges of the mat or blanket are not always uniformly clampedin consequence of which air leaks through the joint proper operation of the frame.

By my present invention, I have overcome the disadvantages of the special clamping device for holding .the sections of the frame in locked relation and have devised a construction wherein the mat is clamped automatically and the locked by utilizing differences sure in such a manner that a predomlnate pressure prevails at one side of the mat which acts in conjunction with certain means to seal theedges of the mat against leakage of air into the space where the printing adjuncts are positioned and also to maintain the two sections of the frame of air reslike means of transfer,

of a printing frame of the character above stated, wherein the two ma n sections.

showing the mat construction tail. 7

Such clamping devices and impairs the frame self-- securely locked together so that the frame may be moved or rotated as required in the printin operation.

For t e purpose of'illustrating my invention, I have shown in the accompanying drawings one form thereof, which is at present preferred by me, although it is to be understood that the various instrumentalities of which my invention consists can be variously arranged and organized and that my"invention is not limited to the precise arrangement and organization of the instrumentalities as herein shown and described.

Figure 1 represents a sectional elevation printing frame embodying myinvention. v a v Fig. 2represents a transverse section of the met or blanket..

Fig. 3 represents an enlarged section more in de- Fig. 4 represents a sectional elevation of the. frame showing the modified form of mat construction.

Fig. 5 represents a section of a portion of the frame and its adjuncts showing another modification of the mat construction.

Fig. 6 represents a further modification of the mat in position within a printing frame. r i

Fig. 7 represents a sectional elevationof of my invention, and

Fig. 8 represents a perspective of the frame showing still another variation of the invention.

1 desi ates the top section of a printing frame, t e same being suitably connected to the bottom section 2 by means of the hinges 3 or like means, wherebythe two'sections of the frame may be swun apart at will and the printing materials p aced in position or removed as the case may be. The top section 1, in the present instance, has the mat or blanket 4 secured to its bottom face and bridging the space inclosed by the four side walls of the section, the said section and mat being adapted to move together, so that in open position of the frame,-the top section and its adjuncts are turned back to permit free access to the bottom section. This bottom section 2 ispreferably mounted upon a suitable stand 5 for rotary or oscillating .movement and carries the plate 6 through which-the light passes to the negative and sensitized material. The plate 6, as here shown, is removably held within a rabbeted portion of the bottomsectron and provides a plane surface to receive the mat and other parts employed in the printing operation. In the resent instance, the mat 4 is provided with a continuous molding 7 following the contour of the mat edges and located in close proximity to said e ges as will be understood, said molding having, in the preferred form, a pair of dependin ribs 8 and 9, the former being circumscribe by the latter, the arrangement bein such that the outer rib 9 is exposed at a points between the frame sections and exposed to atmospheric pressure at all times. The rib 9, it will be noted is inclined with respect to the surface of the plate 6 and the inclination is such that the atmospheric ressure acts angularly to the plate 6 and in a direction to press and hold the said rib against the surface of the plate. The inner rib 8 is preferably shorter than the rib 9, and normally assumes a position at substantially right angles to the surface of the plate 6, so that when the under surface of the mat is subjected to the action of the pump and the vacuum condition is produced, the effect will i be to suck the air around the bottom of the rib 9 and consequently produce a like vacuum condition in the channel or groove 10. The reduction of pressure within this groove 10 results in the outer rib 9 being pressed inwardly at all points by the exterior predominating pressure and since the rib is preferably of a length greater than the space between the plate 6 and the mat 4 in operative position it is pressed. and held directly against the .plate 6 by a pressure per square inch sufliciently great as to lock the frame sections in a positive manner.

In Fig. 4, I have shown a modified construction, wherein the mat 4 is provided with a pair of ribs 11 and 12, the inner one being arranged substantially vertical to the sur face of the glass, while the outer 12 is inolined with respect thereto and corresponds generally in contour and function to e rib 9 above described. The channel or groove 13 between these ribs is a continuous one extending about the mat in close proximity to its outer edges and has communication 'by way of the pipe 14 with theconduit 15 which leads to the vacuum pump. In Fig. 5, I have shown a further modification wherein the inner rib of the molding is provided with ports 16 located at suitable intervals to form communication between the channel 17 and the space between the mat and the plate 6 and serving as exhaust ports for the air drawn out of the pump, whereby the difference in pressures is created at opposite sides of the rib which is exposed to the atmosphere. v p In Fig. 6, a modification is shown, wherein the blanket or mat 18 is provided with a groove 19 adjacent its edges and formed as a continuous channel about the surface of the mat, while the opposite or top side of the mat carries a weight 20 for normally pressing the mat against the plate to insure a ti ht joint. In operation, the exhausting of t e air between the mat and plate of the construction shown in Fig. 6 also produces a condition approximating a vacuum in the groove 19, whereupon the atmospheric pressure acting upon and with the weight causes the parts of the frame to lock automatically and at the same time seals the edges of the mat so that the aforesaid vacuum conditions are maintained as desired during the printing operation.

In Fig.'7, an embodiment of the invention is shown wherein the chamber having communication with the space between the mat and plate is located'exterior of the frame and the construction is preferably as follows:

21 designates a pair of casings located at opposite sides of the frame and forming chambers 22, in each of' which there is a diaphragm member 23, having connected thereto'a hook or looking rod 24:, which is adapted to engage a lug or like latchin device 25 secured to the op osite part 0% the printing frame. Each of the chambers 22 has communication by way of the respective pipes 26 with the exhaust pipe 27, which is in communication with the space between the mat 28 and the plate 29. In this construction it will be evident that as the air is exhausted from the space between the aforesaid mat and plate, the chambers 22 will at the same time be exhausted, whereupon the atmospheric pressure which now predominates will cause the diaphra m to move inwardly as shown in Fig. 7 andthus draw the locking bars 24 into engagement with the respective lugs'25 and maintain the parts of the frame securely locked during the printing operation.

11 Fig. 8, another modification of the invention is shown in which the chamber or chambers having communication with the space to be exhausted is formed in a cylinder 30 secured to one section of the frame and having two pistons 31 therein, each of which has connection with its separate bellcrank 32, which controls the movement of the locking mechanism. As here shown, this mechanism consists of the links 33 suitably fixed to the lower section of this frame and under the control of the movable is tons which in their innermost positions throw the locking links 33 toward the upper frame and 1001: both sections together. Preferably two opposite sides of the frame are equipped with this piston and cylinder locking means and both cylinders have communication with the space to be exhausted sired to through the medium of the pipes 34 and 35, the latter leading to the exhaust pump. It will be noted in cylinder 30 is cut away for purposes of illustration but in practice the c linder is of course complete, though provided with open ends to permit the air pressure to act against the rear sides of the said pistons. It will be understood that in practice, the mat or blanket has its edges securely fastened to one of the frame sections preferably the upper one and in those figures of the drawing in which a distinct fastening means is omitted, it will be understood that the mat is glued or otherwise securely fastened to the frame. It will further be noted that in certain figures, a latch member 36 is shown comprising a hook member pivoted to one section and cooperating with a suitable lug upon the other section and this construction is simply provided as an expedient to prevent separation of the frame sections in case the vacuum should become exhausted by leakage or otherwise and the automatic locking means thus unexpectedly released at a time when the frame sections are in a vertical position. Furthermore, I do not wish to be limited to a frame construction, wherein the two sections are hinged or pivoted'together, since, obviously, they may be entirely separate and distinct, the one being removed from the other when it is deplace the printing adjuncts into position or to have access to-the interior of the frame. In such instances, the one frame may be heavier than the other and thus assist the pressure means to lock the sections together.. referred throughout the specification and claims to the transparent member 6 as a plate. I do not, however, wish to be restricted to the ordinary meaning of a plate, since obviously any. suitable transparent medium may be employed such as a sheet of transparent material or other means capable of transmitting light rays to the negative and sensitized material. In so far as I am aware, I am the first in the art to provide a printing frame of the pneumatic type wherein the reduction of ressure within the chamber to be exhauste causes operation of certain adjuncts of theframe so that the frame parts become self-locking and are held without manuall controlled clamping devices or the like. G enerically, the invention comprises a chamber formed in a suitable medium and operatively arranged with respect to a printing frame, said chamber having communication with the space to be exhausted namely, tive and sensitized material are laced whereby the reduction of pressure in the said space causes a similar reduction within the chamber so that'the atmospheric pressurebecomes predominating and automati-.

Fig. 8, that a portion of the It will also be noted that I have said sections, a

operative position of said parts an the space where the nega cally brings into action certain means where by the two sections of the frame are locked to ether.

t will further-be understood that it is generally customary in practice to press or hold the frame sections together in order to initially compress the mat rib or ribs and "start a partial vacuum which becomes practically complete as the outer edge of the mat tightens down through the exterior predominating air pressure.

It will now be apparent that I have devised a novel and useful device which embodies thefeatures of advantage enumerated as desirable in the statement of the invention and the above description and while I have in the present instance shown and described the preferred embodiment thereof which has been found in practice to give satisfactory and reliable results, it is to be understood that the same is susceptible of modification in various particulars without departing from the spirit or scope of the invention or sacrificing any of its advantages.

What I claim is:

1. In a device of the character stated the combination of a frame formed of top and bottom sections, a plate carried by one of said sections, a'mat of flexible material secured to the other of said frame sections and rovided with a pair of continuous ribs orming a substantially uninterrupted channel bounding the main portion of said mat, the outer rib being of a length greater than the distance between said mat and plate in operative position and seating upon said plate with its edge outwardl disposed and means for producing a con ition approximating a vacuum in said channel whereby said outer rib is held by atmospheric pres sure against said plate and said frame sections are locked to ether.

2. In a device 0 the character stated the combination of a frame formed of top and bottom sections, a plate carried by one of mat of flexi'ble material secured to the opposite frame section and having a continuous groove or channel adjacent its edge, a rib forming a part of said groove and being disposed between the goove and the edge of said mat, said rib ing adapted to seat against said late in d means to produce a condition approximating a vacuum in said groove whereby said rib is held by atmospheric pressure against said plaltie and said frame sections are locked toet er. g 3. In a device of the character stated the combination of a frame formed of top and bottom sections, a plate carried by one of said sections, a mat of flexible material secured to the oppositeframe section havin a continuous rib adjacent its edge, said ri ing its edges positioned the closing of said frame, means to create a being inclined outwardly toward the mat edge and having its outer surface exposed to the atmosphere in operative position of said frame and means to create a condition approximating a vacuum in the space bounded by said rib whereby said frame sections are locked together by air pressure upon the exposed surface of said rib. 1

4. In a device of the character stated the combination of a frame formed of top and bottom sections, a plate of transparent material carried by one of said sections, a flexible mat positioned upon said plate and havto be clamped by condition approximating a vacuum in the space between said mat and plate, means forming a chamber having communication with the space between said mat and plate and means rendered operative by the reduction of pressure in said chamber for locking the, frame sections together.

5. In a device of the character stated, the combination of a frame formed of top and bottom sections, a plate carried by one of said sections, a mat of suitable material seated onsaid plate and provided with a pair of continuous ribs-boundin themajorportion of said mat and one 0 said ribs being longer than the other,-s'aid ribs forming a space or chamber and means for producing a vacuum in said space or chamber whereby said plate and mat are locked together in air tight relation.

In testimony whereof, I have hereunto signed my name.

LIONEL F. LEVY.

Witnesses:

HELEN M. BYRNE, ROBERT M. BARR. 

